Mechanical Behavior of Spheroidized Steel Sheets: Effects of Microstructural Features, Loading, and Boundary Condition Modeling

In this study, the effects of the microstructural features on the mechanical behavior of the spheroidal steel sheets are investigated. The crystal plasticity finite element method is used for simulations. For this purpose, a 2D preprocessing and grain generator software was developed. A series of representative volume elements (RVEs) with different microstructures and boundary conditions were produced. The hardening parameters in the simulations are calibrated according to the available experimental data in the literature. Then, the flow behaviors of the steel sheets under uniaxial tensile load and pure shear were extracted, and the effects of cementite particle fraction and size on steel sheet behavior were investigated. When the cementite particle fraction and size increase, the uniform elongation decreases. Also, the effects of boundary conditions and cementite particle distribution in the steel sheet were studied. It was also shown that symmetric boundary conditions impose more constraints on the material, making the steel sheets stiffer and damage starts earlier. Three RVEs with different particle distributions were modeled. The simulation results showed that by increasing the fraction of particles in the banding structure, the damage starts sooner, and the uniform deformation decreases.